src/arch/x86/include/mode_switch.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2
   3 #include <stddef.h>
   4 #include <stdint.h>
   5
   6 #if ENV_X86_64
   7 int protected_mode_call_narg(uint32_t arg_count,
   8                              uint32_t func_ptr,
   9                              uint32_t opt_arg1,
  10                              uint32_t opt_arg2);
  11
  12 /*
  13  * Drops into protected mode and calls the function, which must have been compiled for x86_32.
  14  * After the function returns it enters long mode again.
  15  * The function pointer destination must be below 4GiB in physical memory.
  16  *
  17  * The called function doesn't have arguments and returns an int.
  18  */
  19 static inline int protected_mode_call(void *func)
  20 {
  21         return protected_mode_call_narg(0, (uintptr_t)func, 0, 0);
  22 }
  23
  24 /*
  25  * Drops into protected mode and calls the function, which must have been compiled for x86_32.
  26  * After the function returns it enters long mode again.
  27  * The function pointer destination must be below 4GiB in physical memory.
  28  * Only the lower 32bits of the argument are passed to the called function.
  29  *
  30  * The called function have one argument and returns an int.
  31  */
  32 static inline int protected_mode_call_1arg(void *func, uint32_t arg1)
  33 {
  34         return protected_mode_call_narg(1, (uintptr_t)func, arg1, 0);
  35 }
  36
  37 /*
  38  * Drops into protected mode and calls the function, which must have been compiled for x86_32.
  39  * After the function returns it enters long mode again.
  40  * The function pointer destination must be below 4GiB in physical memory.
  41  * Only the lower 32bits of the argument are passed to the called function.
  42  *
  43  * The called function has two arguments and returns an int.
  44  */
  45 static inline int protected_mode_call_2arg(void *func, uint32_t arg1, uint32_t arg2)
  46 {
  47         return protected_mode_call_narg(2, (uintptr_t)func, arg1, arg2);
  48 }
  49 #else
  50 static inline int protected_mode_call(void *func)
  51 {
  52         int (*doit)(void) = func;
  53
  54         return doit();
  55 }
  56
  57 static inline int protected_mode_call_1arg(void *func, uint32_t arg1)
  58 {
  59         int (*doit)(uint32_t arg1) = func;
  60
  61         return doit(arg1);
  62 }
  63
  64 static inline int protected_mode_call_2arg(void *func, uint32_t arg1, uint32_t arg2)
  65 {
  66         int (*doit)(uint32_t arg1, uint32_t arg2) = func;
  67
  68         return doit(arg1, arg2);
  69 }
  70 #endif